Many people may not realize it, but the movements we often take for granted -- such as walking and tapping on our keyboards -- release energy that largely dissipates, unused. Several years ago, scientists figured out how to capture some of that energy and convert it into electricity so we might one day use it to power our mobile gadgetry. Achieving this would not only untether us from wall outlets, but it would also reduce our demand on fossil-fuel-based power sources.

The first prototypes of these nanogenerators are currently being developed in laboratories around the world. And now, one group of scientists wants to add another feature to this technology: biodegradability.

The researchers built a nanogenerator using a flexible, biocompatible polymer film made out of polyvinylidene fluoride, or PVDF. To improve the material's energy-harvesting ability, they added DNA, which has good electrical properties and is biocompatible and biodegradable. Their device was powered with gentle tapping, and it lit up 22 to 55 light-emitting diodes.